1. Field of the Instant Disclosure
The instant disclosure relates to a stacked substrate structure; in particular, to a self-sealed stacked substrate structure for use on a printed circuit board.
2. Description of Related Art
The rapid development of the consumer electronics provides new products rapidly to meet the different demands of the consumers. In order to stimulate and trigger the consumers' impulse for purchase, new electronic products are designed towards minimization yet at the same time with stronger functionality. As the printed circuit boards in miniaturized products are required to be thinner and smaller, the development of modern compact circuit boards inevitably trends toward multiple stacked structure with higher component density and enhanced capability. Thus, it is a critical issue at the design stage to obtain a fine electrical conductivity on a printed circuit board, where the signals will not be interrupted and the circuits will function as what is demand.
With reference to FIG. 1, a plurality of electrical components 13 are placed on the first substrate 11 and the second substrate 12. When the first and the second substrates 11 and 12 are put together in a stacked manner, in order to prevent short circuit due to the mutual contact of the electrical components 13 in the substrates 11 and 12, a frame 14 is often arranged between the first and the second substrate 11 and 12 for creating separation there-between. For the structure of the frame 14, the frame 14 is designed as a hollow structure defining a receiving space between when sandwiched by the first and the second substrates 11 and 12. Therefore, the electrical components 13 of the first and the second substrates 11 and 12 can be received therein during assembly. Furthermore, by the orientation of the FIG. 1, the top and bottom of the frame 14 has a welding pad 15 formed respectively thereon. The first substrate 11 is connected electrically to the second substrate 12 through the welding pad 15, the solders 16, and the frame 14.
Conventionally, for the conformal shielding technology, the first substrate 11 and the frame 14 are connected together, while the second substrate 12 and the frame 14 are connected together. Furthermore, a package layer (not labeled) will be disposed on the first substrate 11. During the latter coating process of the conductive layer, in order to prevent the conductive substances from penetrating into the gaps between the first substrate 11 and the frame 14, or the gaps between the second substrate 12 and the frame 14, an insulating colloid 17 will be injected therein to seal up the gaps. Specifically speaking, the colloid 17 made of a material selected from the group consisting of the epoxy resins or the thermosetting colloids and etc. The gaps on the periphery of the welding pads 15, and the gaps between the frame 14 and the first and the second substrates 11 and 12 will be sealed up using the colloid 17. Hence, the conductive substances can be avoided from contacting the welding pads 15 during the latter coating process. Nevertheless, the colloid 17 injection method requires multiple manufacturing processes which turn out to be economically disadvantageous. Furthermore, the amount, forming position . . . of the colloid upon injection is uneasy to be controlled. Thus, providing a simpler manufacturing process excluding the colloid injection will best enhance the production efficiency.